Radio receiving system



Feb. 7, 1928. 1,658,740

:1. w. RICE RADIO RECEIVING SYSTEM Filed Nov. 21, 1922 3 Sheets-Sheet 1 All Chester-WRice.

b y His Attorney Feb. 7, 1928. I 1,658,740

c. w. Rlcr;

RADIO RECEIVING SYSTEM Filed Nov. 21, 1922 3 Sheets-Sheet 2 64. H95 ay- Im/entor: C he sterw. Rice by His Attorney Feb. 7,1928. v 1,658,740 c. w. RICE RADIO RECEIVING SYSTEM Filed Nov. 21, 1922 I5 Sheets-Sheet 3 0, A {WV V wNW-- Ordef'qf mm/enter: Chester W. Rica.

by W His Attorney Patented Feb. 7, 1928.

CHESTER W. RICE, OF SCHENECTADY, NEW YORK, ASSIGNOR- T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW/V YORK.

R AIDIO RECEIVING SYSTEM.

Application filed November 21, 1922. Serial No. 602,426.

My present invention relates to radio receiving systems and more particularly to systems for obtaining a high degree of selectivity in reception.

For the purpose of eliminating interfer ence from stations and static it is now recognized that highly directive antennae are especially effective. One form of unidirectional antenna which has been found to be highly successful in practice is that now known in the art as the wave antenna, such as described in Beverage Patent 1,381,089, Juiie 7, 1921. The directivity of the wave antenna increases with its length, but not proportionally thereto. For example, taking the area of the directive curve of a wave antenna having light velocity and zero attenuation one wave length long as 100%, it can be calculated that for Antenna lengthx, area 100 per cent.

Antenna length=2,\, area 81 per cent.

Antenna length=-i/\, area= per cent. It appears from the above that the area of the irective curve decreases rather slowly with increased length. If on the other hand instead of adding new antennae on the end of the existing antenna in the same straight line the two antennae are placed side by side at some distance apart and the signals from the two combined, a much sharper directive curve may be obtained. The relative areas of the directive curves may then be as follows:

One wave antenna A long, A=100 per cent.

Two parallel wave antennae each )t long and spaced 5, A apart, A=52 per cent.

Three parallel wave antennae each A long and spaced A apart, A=34 per cent.

In this case it is seen that the areas of the directive curves are roughly inversely proportional to the total length of the antenna used. It is therefore apparent that the latter arrangement is economically superior to the former.

As will be shown in the description that follows there are numerous other forms of receiving antennae which may be combined in various ways to produce correspondingly sharper directive curves than can be obtained with a single antenna. In the description which follows I will refer to the wave antenna as an end on receiver since .it receives signals with maximum intensity when pointing toward the transmitter, and

I will refer to the arrangement consisting of a row of antennae placed perpendicular to the signal direction as a broadside receiver since it normally receives signals with a maximum intensity When a signal strikes the various elements simultaneously.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims; my invention itself, however together with certain of the objects and advantages thereof will best be understood by reference to the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a diagrammatic representation of a receiving system employing three-wave antennae; Figs. 2 and 3 are diagrams illustrating the operation of such a. receiver; Figs. 4', 5 and 6 are directive curves illustrating the increase in directivity which may be obtained by employing two or three parallel wave antennae; Figs. 7 and 8 are diagrammatic representations of other antenna arrangements which may be employed to obtain similar results to that which may be obtained with the arrangement of Fig. 1.

In Fig. 1 I have shown three-wave antennae 1, 9. and 3, each of which points in the general direction of the signal which it is desired to receive. The ends 13,, B B of theseantennae are provided with the usual reflection transformers R R R to permit of the reception at the ends A A A of signals traveling in the direction from A to 13,. At the ends A A A, there are pro vided output transformers T, T T 8,, S S as indicated, for supplying signaling and compensating currents to the balancedtransmission lines L L L M M M by means of which the desired currents are transmitted to the receiving station. Damping resistances C may be inserted across the transmission lines to Prevent undesired flections. I have provided at the receiving station artificial lines N N N 0 O 0 or other time or phase adjusting circuits to which the currents conveyed over the transmission lines are supplied by a series of transformers 4, 5, 6, 7, 8 and 9. Currents from the artificial lines are supplied by means of intensity couplers I,, I 1,, K K K to the input circuits of the coupling tubes 10, 11 and 12.

The output circuits of the coupling tubes 10, 11and12are connected-through trans formers 13, 14 and 15 to'artificial lines P P P and current may be supplied'from these artificial lines through intensity couplers V ,,V V 'to the input circuit of a combining tube 16. Current may be supplied from the output circuit of this tube 16 tothe tuned circuit 17 from-which the'desired signaling current is Supplied to the receiver 18. It will be understood that'the vacuum tubes indicated will be connected in the usual manner, part of the connections havin been omitted from the drawing for 1 the purpose of simplification. 1 In adjusting the systems described to obtain the desired results the sliding connections .19, 20, 21, 22, 23 and 24' on the artificial lines are first adjusted for each of the wave antennae to give the best signal reception from that antenna alone. In order to combine 7 the currents from the different'units in such a way as to obtain the maximum directivity 1 and reception, the sliders 25, 26. and 27 onsimultaneously and sets up like currents in.

each of the antenna units. The signaling currents are conveyed over the transmisslon lines and finally appear as variations in the plate currents of the several coupling tubes 10, 11 and 12. In general, the currents will not arrive simultaneously or in .phasein the plate circuits of these coupling tubes since the different antennae will be at'ditferent distances from the receiving station.

. proper adjustment ofphase adjustersPi, P

P the different currents may-bebrought in phase so thattheir efiects add directly in the secondaries of the intensity couplers V V V and therefore their. efiects are added in combining tube 16. For the case a single unit.

of equal intensitiesin the different units the total eflfect will then be three times thatrot vAssume/now that the adjustment which gives equal time transmission and equalamplitude from the. several antennae is retained but assume that the signal from an angle instead from the direction of the arrow. The

currents received by'the different units will still be 'equal'injvalue but. will not arrive at the receiver simultaneously and thereforeinstead of adding all in phase they will add at certain phase angles and the resultant will be less than three times the current which would he produced in a singlev unit 'by' the s-ignal coming from the assumed angle.

To illustrate the method of calculating the directive curve, let as assume the case of a;

row of like units spacedequal distances i apart. I Let 6=Direction angle of signal. 0Z=Distance apart of the antenna in wave length units.

B=Phase angle corresponding to the an- '7 tenna spacing cl. 1

Ie=Currentj from single unit at angle 9;

lay distance 6 It cl is expressed in wavelength units, a- 360 phase displacement the ph'ase angl thensince one wave length corresponds to ,8 will be B=860 d; lVe then have ;5=,8 sin 9.

rb =360 Xd Sin 9. Having determined the phase for a given directionof the signal, we can their proper magnitudes I and each difangle as illustrated in Figure3.

process as many points on the polardirective curve as desired may be calculated.

from the triangle Fig; Y r s5 75f V b=Delay distance in wave length units. =Phase angle-correspondingtothe dclay oft" the several antenna currents with 505 fering from thepr-evious one by the phase i The chord drawn between the first andlast vector; constitutes the resultant current for the. pa r ticular angle under consideration. .By this Y The directive curves Fig. 5 and 6 were 7 derived from Fig 4 by this process. The units assumed are wave antennae each one zero attenuation.

7 Wave length long having light velocityand Fig. 4 is the directlve curve forthe single wave antenna; Fig. 5 f

antennae spaces )t apart Fig. 6' the. di

these Wave antennae, each A apart.

The units of which the broad siderows',

are composed may instead ofbeing made .u

of wave antennae consist of any of thewell the resultant directive curve for two suchhj rective curve ofthecombination o f-three of r known unidirectional combinations. In Fig.

7 Ihave shown two ground antennae in each unit, spaced apart, that is, one behind the other in signal direction and these-maybe it 5- i 1151* rection opposite to that of the signal. The.

adjusted. to give zero reception from the dicurrents fronr the various antennae in this arrangement are: conveyed tothe recelvlng station over thetransmission lines L L5, I1 M M M- as in the arrangement shown n Fig. 1. -The same station apparatus may be employed for any of these alternative] antennae systems and the procedure of adjustmentand operation will'be the same for,

each While-Ihave shown in Fig. 1 only the circuit connections necessary for receiving a f 1 z single signal, the arrangement shown in Fig.

1 as well asthe arrangement shown in Fi 7 may equally well be employed for multip le x reception of signals all of which'come from one direction or part from one direction and part from the opposite direction, it being necessary in this case to provide additional sliders 28 to 33, inclusive, for securing the necessary phase adjustments, and a duplicate set of coupling tubes, combining tube and intensity couplers for each separate sig nal which is to be received.

In the arrangements thus far described I have considered only a broad side row made up of a number of separate units spaced an appreciable traction of a Wave length apart perpendicular to the signal direction, for example, or more. Another convenient arrangement whereby highly directive results may be obtained is to use two multiple tuned or infinite velocity antennae spaced apart one back of the other. This method of producing a unidirectional broadside receiver is illustrated in Fig. 8. Antennae 37, 38 are of the multiple tuned type and therefore adjusted so that the currents in all of the down leads are in phase. An antenna of this type is the equivalent of'a plurality of static antennae connected by an infinite velocity transmission line. Transmission lines L and L convey the signals from each antenna to the receiving station where the phase and intensity adjusting apparatus N N and 1 I is located. The effects of the desired signaling currents are then combined in series on the grid of the combining tube 39 and the receiving set 18 is supplied through the tuned circuit 17 from the plate circuit of the combining tube. One of these antennae alone consists of a highly directive bidirectional broadside receiver. The combination of the currents from two such units one placed behind the other so that the wave impulses coming from the direction opposite the arrow of Fig. 8 will cancel while the signal coming in the direction of the arrow will not cancel results in a highly directive unidirectional broadside receiver. The method of combining currents from difierent units employed in this case is the equivalent of that indicated in the system illustrated in Fig. 7 as it is immaterial whether the first combination is made of currents from a r w extending in the direction of the signal and the second combination is made or currents from a plurality of such rows or the first combination is made of currents from a row extending at a right angle to the signal direction and the second combination is made of currents from a plurality of such rows.

While I have shown and described the preferred embodiments of my invention. it will be apparent that many modifications in the form, number and arrangement of the antennae employed as well as in the manner in which the currents from the different antenna units are combined, may be made without departing from the scope of my invention as set forth in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. The combination in a radio receiving system of a plurality of parallel unidirectional receiving antennae each having a horizontal length as great as the wave length of the signal to be received and separated from each other by a substantial fraction of awave length of the signals to be received, a receiving apparatus and means for combining the currents received upon the diiierent antennae in the receiving apparatus.

2. The combination in a radio receiving system of a plurality of parallel wave antennae each having a horizontal length as great as the wave length of the signal to be received separated from one another by at least a halt' wave length of the signals to be received in a direction substantially at right angles to that of the signal to be received, a receiving apparatus and means for combining the currents received upon the difierent antennae in the receiving apparatus.

The combination in a radio receiving system of a plurality of parallel horizontal antennae separated from one another by a substantial traction of a wave length of the signals to be received in a direction substantially at right angles to that of the sig nal to be received, a receiving apparatus and means for combining the currents received upon the different antennm in the receiving apparatus.

4. The combination in a radio receiving system of more than two receiving antennae rranged in a row extending in a direction substantially at right angles to the direction of the signals to be received and separated from each other by a substantial fraction of a wave length of the signals to be received, a receiving apparatus and a pair of balanced transmission lines connecting each antenna with the receiving apparatus.

5. The combination in a radio receiving system of more than two receiving antennae arranged in a row extending in a direction substantially at right angles to the direction of the signals to be received and separated from each other by a substantial fraction of a wave length of the signals to be received, a receiving apparatus, a pair of balanced transmission lines connecting each antenna with the receiving apparatus, and means at the receiving apparatus for adjusting the phase and intensity of the currents impressed from each transmission line upon the receiving apparatus.

6. The combination in a radio receiving system of a plurality of directive receiving units, a pairof phase adjusting circuits associated with each of said units, a coupling tube for each unit having its input circuit adjustably coupled toboth of said phase adjusting circuits, and means for impressing,

upon the receiving apparatus currents of ad-' justed phase andi'ntensity from the output circuits of all of the coupling tubes.

c 7. The combination in a radio receiving system of a plurality '.of directive receiving units, a pair of phase adjusting circuits associated with each .unit and adapted to receive therefrom currents derived'from Waves reaching said units from different directions,

- a coupling tube for'each'unit having its'in put circuit adj ustably associated with both of said phase adjusting c1rcuits,a receiving apparatus, and means for impressing upon the receivingapparatus from all of the coufrom the corresponding receiving unit, and

plin'g" tubes currents of adjusted phase and intensity. 7

'8. The combination in a radio receiving system of a pluralityiof directive receiving units, a pair of phase adjusting circuits assoc ated with each receiv ng unit, a coupllng tube for each unit having its input circuit adjustably coupled to-the two phase adjust ing'circuits associated with that unit, a phase adjusting circuit associated ith the output circuit of each coupling tube and-means for adjustably coupling the phase adjusting circuits of all of the tubes to a receiving apparatus. 1

9. The combination in'a radio receiving system of a plurality of directive receiving units, a coupling tube associated with each receiving unit, meansfor effecting'a desired neutralization of interferingimpulses in the input circuit of each couplingtube comprising means for combining in selected phase and intensity two dlfferent currents derived means for impressing upon receiving Zappasystem of a plurality of directive ireceivin units a coupling tube associated With eac 40 ratus currents of adjusted phase and intense" f ity from the output circuits of all of the cou-' v r pling tubes." 7 V x 10. The combination in a radio receiving f the output circuits ofall ofthe coupling;

tubes. I 11 Thezcombination in a radio receiving'flm system of a plurality of directive receiving, units,v a coupling tube associated with eaj'chQ' receiving unit, means for e'ffecting'adesiredneutralization of interfering impulses in the input circuit of each coupling tube compriseing means for combining in selected phase and intensity two difierentcurrents'derived from the corresponding receivingjunit, a f

combining'tube, means forimpressingnupon i i the input circuit of said combining tubecur-c rents of adjusted phase and intensity from the output, circuits of all of the coupling tubes, and a receiving apparatus associate wfth thebutput circuit ofthe combining tube. r

hand.

Inwitness whereof I have hereuntoset 15- CHESTER w. nen; i 

